Inductive signaling plays a critical role in both normal and disease development as developmental pathways that become unregulated in the adult can lead to abnormal patterning, overproliferation and neoplasia. One signaling pathway that is involved in several patterning events during embryogenesis is that triggered by secreted sonic hedgehog (Shh) (Echelard, Y., Epstein, D. J., St-Jacques, B., Shen, L., Mohler, J., McMahon, J. A. & McMahon, A. P., Cell 75, 1417-1430 (1993); Riddle, R., Johnson, R. L., Laufer, E. & Tabin, C.,Cell 75, 1401-1418 (1993); Krauss, S., Concordet, J.-P. & Ingham, P. W, Cell 75, 1431-1444 (1993); Roelink, H., Augsburger, A., Heemskerk, J., Korzh, V., Norlin, S., Ruiz i Altaba, A., Tanabe, Y., Placzek, M., Edlund, T., Jessell, T. M. & Dodd, J., Cell 76, 761-775 (1994)). Shh binding to the membrane patched (ptc)-smoothened (smo) receptor complex elicits a cascade of cytoplasmic signal transduction events, including the inhibition of protein kinase A (PKA) (Fan, C.-M., Porter, J. A., Chiang, C., Chang, D. T., Beachy, P. A. & Tessier-Lavigne, M., Cell 81, 457-465 (1995); Hynes, M., Porter, J. A., Chiang, C., Chang, D., Tessier-Lavigne, M., Beachy, P. A. & Rosenthal, A., Neuron 15, 35-34 (1995); Concordet, J.-P., Lewis, K. E., Moore, J., Goodrich, L. V., Johnson, R. L., Scott, M. P. & Ingham, P. W., Development 122, 2835-2846 (1996); Epstein, D. J., Marti, E., Scott, M. P. & McMahon, A. P., Development 122, 2885-2894 (1996); Goodrich, L. V., Johnson, R. L., Milenkovic, L., McMahon, J. A. & Scott, M. P., Genes Dev. 10, 301-312 (1996); Hammerschmidt, M., Bitgood, M. J. & McMahon, A. P., Genes and Dev. 10, 647-658 (1996); Marigo, V., Johnson, R. L., Vortkamp, A. & Tabin, C. J., Dev. Biol. 180, 273-283 (1996); Stone, D. M., Hynes, M., Armanini, M., Swanson, T. A., Gu, Q., Johnson, R. L., Scott, M. P., Pennica, D., Goddard, A., Phillips, H., Noll, M., Hooper, J. E., de Sauvage, F. & Rosenthal, A., Nature 384, 129-134 (1996)) that leads to the transcription of the zinc finger transcription factor gene Gli1 (Marigo, V., Johnson, R. L., Vortkamp, A. & Tabin, C. J., Dev. Biol. 180, 273-283 (1996); Lee, J., Platt, K. A., Censullo, P. & Ruiz i Altaba, A. , Development (1997)). Gli1 is a proto-oncogene first isolated as an amplified gene in a glioma that can transform fibroblasts in cooperation with E1A (Kinzler, K. W., Bigner, S. H., Bigner, D. D., Trent, J. M., Law, M. L., O'Brien, S. J., Wong, A. J. & Vogelstin, B., Science 236, 70-73 (1987); Ruppert, J. M., Vogelstein, B. & Kinzler, K. W., Molecular and Cellular Biology 11, 1724-1728 (1991)). Gli1 is a member of a family comprising two other related genes: Gli2 and Gli3 (Ruppert, J. M., Vogelstein, B., Arheden, K. & Kinzler, K. W., Mol. Cell Biol. 10, 5408-5415 (1990); Hui, C.-C., Slusarski, D., Platt, K. A., Holmgren, R. & Joyner, A. L., Developmental Biology 162, 402-413 (1994)). However, only Gli1 has been shown to be a target of Shh and mimic its effects (Lee, J., Platt, K. A., Censullo, P. & Ruiz i Altaba, A., Development (1997)). In Drosophila, hedgehog signaling (Forbes, A. J., Nakano, Y., Taylor, A. M. & Ingham, P. W., Development Supplement 115-124 (1993)) similarly leads to the action of cubitus interruptus (ci), a Gli homolog that activates transcription of hedgehog-target genes (Domínguez, M., Brunner, M., Hafen, E. & Basler, K., Science 272, 1621-1625 (1996); Alexandre, C., Jacinto, A. & Ingham, P. W., Genes and Dev. 10, 2003-2013 (1996); Hepker, J., Wang, Q.-T., Motzny, C. K., Holmgren, R. & Orenic, T. V., Development 124, 549-558 (1997); von Ohnen, T., Lessing, D., Nusse, R. & Hooper, J. E., Proc. Natl. Acad. Sci. USA. 94, 2404-2409 (1997); Mullor, J. L., Calleja, M., Capdevila, J. & Guerrero, I., Development 124, 1227-1237 (1997)).
One of the processes in which Shh signaling is involved is the differentiation of ventral neural tube cell types acting as a notochord and floor plate-derived signal (Echelard, Y., Epstein, D. J., St-Jacques, B., Shen, L., Mohler, J., McMahon, J. A. & McMahon, A. P., Cell 75, 1417-1430 (1993); Roelink, H., Augsburger, A., Heemskerk, J., Korzh, V., Norlin, S., Ruiz i Altaba, A., Tanabe, Y., Placzek, M., Edlund, T., Jessell, T. M. & Dodd, J. ,Cell 76, 761-775 (1994); Martí, E., Bumcrot, D. A., Takada, R. & McMahon, A. P., Nature 375, 322-325 (1995); Ruiz i Altaba, A., Roelink, H. & Jessell, T. M., Mol. Cell. Neurosci. 6, 106-121 (1995); Chiang, C., Litingtung, Y., Lee, E., Young, K. E., Corden, J. L., Westphal, H. & Beachy, P. A., Nature 383,407-413 (1996);Ericson, J., Morton, S., Kawakami, A., Roelink, H. & Jessell, T. M., Cell 87, 661-673 (1996)). Previous work by the applicants herein on the role of sonic hedgehog signaling during neural plate patterning in frog (Xenopus laevis) embryos demonstrated that cells becoming floor plate respond to Shh by expressing Gli 1, Pintallavis and HNF-3β, critical transcription factors that themselves can induce the differentiation of floor plate cells (Lee, J., Platt, K. A., Censullo, P. & Ruiz i Altaba, A. Gli1 is a target of sonic hedgehog that induces ventral neural tube development. Development, 124(13):2537-52 (1997); Ruiz i Altaba, A., Roelink, H. & Jessell, T. M. Restrictions to Floor Plate Induction by hedgehog and Winged Helix Genes in the Neural Tube of Frog Embryos. Mol. Cell. Neurosci. 6, 106-121 (1995); Ruiz i Altaba, A., Cox, C., Jessell, T. & Klar, A. Deregulated Expression of the Midline Transcription Factor Pintallavis Induces Ectopic Expression of a Floor Plate Marker. Proc. Natl. Acad. Sci. USA 90, 8268-8272 (1993); Ruiz i Altaba, A., Prezioso, V. R., Darnell, J. E. & Jessell, T. M. Sequential expression of HNF-3β and HNF-3 by embryonic organizing centers: the dorsal lip/node, notochord and floor plate. Mech. Dev. 44, 91-108 (1993)).
In addition to effects on neural tissue, it has been found that ectopic expression of Shh and Gli1 also leads to the activation of Shh signaling target genes in epidermal non-neural ectoderm. Injected Shh induced the ectopic expression of Gli1, HNF-3β and Shh (Ruiz i Altaba, A., Roelink, H. & Jessell, T. M., Mol.Cell. Neurosci. 6, 106-121 (1995)), and ectopic expression of Gli1 induced the ectopic expression of HNF-3β and Shh (Lee, J., Platt, K. A., Censullo, P. & Ruiz i Altaba, A. Gli1 is a target of sonic hedgehog that induces ventral neural tube development. Development (1997)). Together, these results indicated that both neural and epidermal cells have functional reception and transduction mechanisms for Shh and can respond by activating the expression of Shh/Gli1 target genes even though epidermal cells do not normally receive the Shh signal at this stage.
Furthermore, SHH signaling has been implicated in many aspects of animal development, acting through the transmembrane proteins PATCHED1 (PTCH1) and SMOH to activate the GLI zinc-finger transcription factors (Ingham, P. & McMahon, A., Genes Dev. 15, 3059-87 (2001); Ruiz i Altaba, A., Sanchez, P. & Dahmane, N., Nat. Rev. Cancer 2, 361-372 (2002).
Lung cancer is the leading cause of cancer deaths in both men and women in developed countries and is a growing problem in developing countries (Schottenfeld, 1996). The lack of biomarkers for early detection and ineffective chemotherapies are the main reasons why the prognosis of patients with lung cancer remains poor. Thus, new methods for early detection such as biomarkers, new approaches for lung cancer chemoprevention and new drugs based on rational targets need to be developed. Increased understanding of the molecular and cellular basis of the initiation events and mechanisms underlying drug resistance will be needed to achieve these goals.
Considering the adverse side-effects and expense associated with treating cancer, in particular, lung cancer, better diagnostic and prognostic tools are needed. Therefore, there is a need to identify other factors that can be used for the early detection of cancer, as well as the means to predict the progression of cancer, including but not limited to, lung cancer. In addition, there is a need to identify new therapeutic strategies for treating cancer, including, but not limited to, lung cancer.
While GLI1 has been implicated in a number of cancers, including basal cell carcinoma (Dahmane et al., 1997), and medulloblastoma (Goodrich et al., 1997), the role for GLI1 in human lung cancers remains unknown. Indeed, uncontrolled activity of this pathway is sufficient to induce medulloblastomas in mice (Goodrich et al., 1997) and ectopic expression of GLI1 in the embryonic frog epidermis or GLI1 and GLI2 in the mouse epidermis results in the development of basal-cell carcinoma-like and other skin tumors (Dahmane et al., 1997; Nilsson et al., 2000; Grachtchouk et al., 2000).
The present application is directed to the identification of the role of the gli genes and the GLI proteins in lung cancer and to methods and compositions for treating and/or diagnosing this disease.
The citation of any reference herein should not be construed as an admission that such reference is available as “Prior Art” to the instant application.